SNAP 8 Reactor Test Program

The SNAP 8 reactor is a heat source suitable for long endurance 10 to 50 kw space electric power supplies. The major milestones in the development of this reactor are three ground tests: the SNAP 8 Experimental Reactor (S8ER), the SNAP 8 Developmental Reactor Mockup (S8DRM), and the SNAP 8 Developmental System (S8DS). The S8ER test was completed in April 1965 after 500 days of nuclear operation. S8ER demonstrated long-term operation of the SNAP 8 reactor by operating for 1 year at thermal power levels in the range 400 to 600 kwt with a 1300° F coolant NaK outlet temperature. This test included a continuous run of 5000 hours. The continuous operation of S8ER was due in part to a facility reliability upgrading undertaken to minimize unnecessary test interruptions caused by instrumentation malfunctions or electrical disturbances at the test site. The second SNAP 8 reactor, S8DRM, has undergone a series of nonnuclear tests to verify the performance of the automatic startup and control drive system, and to determine the reactor's environmental capabilities (e.g., shock, vibration, vacuum, and temperature). The third SNAP 8 reactor test, S8DS, will start nuclear operation late in 1966. The objective of this test is to verify the SNAP 8 flight reactor design, and to operate the reactor coupled to a power conversion system.